Cooling systems for engines are well known. Exhaust gas recirculation (EGR) coolers are cooling systems that are typically mounted on an engine intake manifold to cool exhaust gas that passes through the engine intake manifold. Coolant fluid passes around tubes within the EGR cooler to cool the exhaust gas that passes through the tubes. One problem with conventional EGR coolers is that the inside of the tubes get covered with soot and ash. Such fouling from the soot and ash adversely affects the efficiency of the EGR cooler over time by reducing the efficiency of the tubes. Build up of fouling inside the tubes may lead to increased intake manifold temperatures and nitrogen oxide (NOx) emissions. To compensate, EGR coolers are typically designed significantly larger to account for performance loss over time.
Accordingly, what is needed is an improved cooling system that addressing the soot and ash problem. The present invention addresses such a need.